JP4895383B2 - Filling degree inspection apparatus and filling degree inspection method - Google Patents

Description

  The present invention relates to a filling degree inspection apparatus and a filling degree inspection method for inspecting the filling degree of a grout of a sheath tube using a steel material installed inside a concrete structure such as a bridge of an expressway, and more particularly to concrete. The present invention relates to a technique capable of accurately inspecting the degree of filling of grout in a sheath tube without squeezing.

  A sheath tube for prestressing the bridge is provided inside the bridge such as an expressway. In this sheath tube, a PC steel wire, a PC steel rod or the like (PC steel material used for applying prestress) as a tension material is provided. Such a sheathed PC steel wire, PC steel rod or the like corrodes if there is a cavity in the sheath tube, and therefore the sheath tube is filled with grout for preventing corrosion.

  However, due to poor construction, cavities and bubbles remain inside the sheath tube (hereinafter referred to as “unfilled grout”), and if the PC steel wire or PC steel rod corrodes, the PC steel wire or PC steel rod The prestressing force that has been applied will not function as designed, and the durability of the bridge may be reduced. The unfilled state of the grout inside the sheath tube can be seen even in bridges that have already been constructed. Therefore, non-destructive inspection technology that can inspect the unfilled portion of the grout without destroying the bridge (inspection device for grout filling in the sheath tube) And methods).

  18 is a schematic diagram showing the principle of a conventional filling degree inspection device 200 for grout in a sheath tube, FIG. 19 is a graph showing the results detected by the filling degree inspection device 200, and FIG. 20 is a bridge in the filling degree inspection device 200. It is explanatory drawing which shows an example of a test | inspection. In the figure, E indicates propagation of elastic waves. In FIG. 18, for convenience of explanation, the sheath tubes 220 and 220A are shown side by side.

  As shown in FIG. 18, the test specimen in the case of performing the filling degree inspection of the grout in the sheath pipe is a sheath pipe 220 embedded in the concrete 210, and a steel provided in the sheath pipe 220 and having an end exposed from the concrete 210. It has a rod 221 and a grout 222 filled between the sheath tube 220 and the steel rod 221.

  For convenience of explanation of the filling degree test, in addition to the sheath tube 220 that is normally filled, a sheath tube 220A that is not filled with the grout 222 is also shown in FIG.

  As shown in FIG. 18, the filling degree inspection apparatus 200 includes an impact applicator 230 such as a hammer or a steel ball for applying an impact to the end of the steel rod 221, and the impact application point by the impact applicator 230. The trigger waveform receiving sensor 240 provided near the ends of the sheath tubes 220 and 220A, and the sheath tubes 220 and 220A on the side where the trigger waveform receiving sensor 240 is installed are the other sheath. Propagation waveform receiving sensor 250 provided at the center of the ends of tubes 220 and 220A, filter 260 connected to propagation waveform receiving sensor 250, amplifier 270 connected to filter 260, and connected to amplifier 270 For example, it is an oscilloscope or the like and includes a detector 280 having a first CH 281 and a second CH 282.

  The trigger waveform receiving sensor 240 is connected to the first CH 281, and the propagation waveform receiving sensor 250 is connected to the second CH 282.

  In the sheath tube grout filling degree inspection device 200 configured as described above, first, an impact is applied to the steel rod 221 by the impact applicator 230. At this time, the trigger waveform is received by the trigger waveform receiving sensor 240 provided near the impact application point. When an impact is applied to the steel bar 221, an elastic wave propagation E is generated in the steel bar 221. The propagated elastic wave (propagation waveform) is received by the propagation waveform receiving sensor 250.

  The trigger waveform is detected by the first CH 281 of the detector 280. On the other hand, since the noise is removed from the propagation waveform through the filter 260 and the amplifier 270 and the waveform is amplified, the SN ratio is improved. Then, a propagation waveform with a good S / N ratio is detected by the second CH 282 of the detector 280. In this way, the trigger waveform and the propagation waveform are detected.

In FIG. 19, the trigger waveform detected by the detector 280 is shown on the upper side, and the propagation waveform is shown on the lower side. Since the propagation waveform is detected from time To, the time from when the trigger waveform is detected until the propagation waveform is detected at time To is defined as propagation time T. Furthermore, if the length of the steel bar is L, the propagation velocity V of the propagating waveform is
V = L / T
Is required.

  Here, regarding the relationship between the filling rate of the grout and the propagation speed, the propagation speed decreases as the filling rate of the grout increases. That is, the propagation speed Vj when the grout is filled is slower than the propagation speed Vm when the grout is not filled. For example, if the propagation velocity Vm when no grout is filled is 5500 m / s, the propagation velocity Vj when the grout is completely filled is 5225 m / s. Therefore, the difference in propagation speed between the sheath tube 220 filled with grout and the sheath tube 220A not filled with grout is about 5 to 8%.

  The inspection of the sheath tube used in the actual bridge is performed on the basis of the difference in propagation speed between grout filling and non-filling of about 5 to 8%. By comparing the difference of 5 to 8%, it can be determined whether the sheath tube is filled with grout or not.

  In addition, there is also known a method for inspecting a grout filling degree in a sheath tube for obtaining an attenuation constant of a received waveform (see, for example, Patent Document 1). This inspection method has the characteristic that the damping constant is large when the grout is filled, but the damping constant is small when the grout is not filled. Use. Here, the attenuation constant corresponds to the vibration duration time of the propagation waveform shown in FIG. 19, and when the attenuation constant is small, the vibration attenuation time of the propagation waveform becomes long, and when the attenuation constant is large, the vibration of the propagation waveform The decay time is shortened. In this way, the inspection is performed to determine whether the grout is filled or not based on the vibration damping time (damping constant).

The above-described method for comparing propagation velocities and the method for obtaining the propagation waveform attenuation constant are the mainstream methods for checking the degree of grout filling in the sheath tube. When these inspection methods are performed on an actual bridge, as shown in FIG. 20, a part 210 </ b> A of the concrete 210 is hung and the steel bar 221 is exposed on the surface of the concrete 210. An impact is directly applied to the exposed steel rod 221 by the impact applicator 230, and the propagation waveform generated by the impact application is received by the propagation waveform receiving sensor 250 to inspect.
JP 2000-105227 A

  The above-described method for inspecting the grout filling degree in the sheath tube has the following problems. In other words, in the method of comparing the propagation speed, the length L of the steel rod may not be accurately determined by inspection with an actual bridge, and the impact energy by the impact applicator is relatively small. Is difficult to identify. Furthermore, the difference between the propagation velocity Vm and the propagation velocity Vj is only 5 to 8%, and measurement accuracy is required. As a result, errors may occur and accurate inspection may not be possible.

  In addition, in the method of obtaining the attenuation constant, there are various types of mode waves, etc. that propagate, and there is a possibility that an erroneous determination will be made if the measurer does not know which mode wave is currently present. is there. In addition, it is difficult to determine which mode wave is used on site. In addition, there is a case that an absolute evaluation cannot be performed by these inspection methods.

  Furthermore, in any of the above inspection methods, since it is necessary to hang concrete and expose the end portion of the sheath tube, the cost and time required for the inspection are required, and repair after the inspection is also necessary. Depending on the repaired state, rain water or the like may penetrate into the sheath tube due to aging or the like.

  FIG. 21 is an explanatory view showing an example of an inspection method by a conventional filling degree inspection apparatus 200 using a steel wire (PC steel wire) 223 for the sheath tube 220. As shown in FIG. 21, when the PC steel material used for the sheath tube 220 is a steel wire 223, the size of the impact applicator 230 is set so as not to interfere with other steel wires 223 because of the shape and the number of wires used. You must make it smaller. However, if the impact applicator 230 is made smaller, the impact will also be reduced, so the SN ratio will be worsened and the inspection accuracy will be reduced. Furthermore, when a thin steel material having a steel material diameter of about 7 mm is used, there is a problem that it is theoretically difficult to apply the inspection method.

  Therefore, an object of the present invention is to provide a sheath tube grout filling degree inspection apparatus and a sheath tube grout filling degree inspection method capable of accurately inspecting the grout filling degree in the sheath tube without holding concrete. .

  In order to solve the above problems and achieve the object, the filling degree inspection apparatus and filling degree inspection method of the present invention are configured as follows.

  In a filling degree inspection apparatus that is installed inside a concrete structure and inspects the filling degree of a grout of a sheath pipe having a steel material, an impact applying means that gives an impact to the concrete surface facing one end of the sheath pipe; A propagation waveform receiving sensor provided on the surface of the concrete facing the other end of the sheath tube and detecting a vibration generated in the sheath tube by the impact as a propagation waveform; and a zero crossing time based on the propagation waveform. Zero cross time calculation means for calculating, zero cross frequency calculation means for calculating the zero cross frequency based on the calculated zero cross time, and zero cross frequency normalized value calculation for calculating the zero cross frequency normalized value by normalizing the calculated zero cross frequency And the above-mentioned group based on the calculated zero cross frequency normalized value. Characterized in that it comprises a determining means for determining the filling degree of out.

  In a filling degree inspection method that is installed inside a concrete structure and inspects the filling degree of a grout of a sheath tube having a steel material, an impact applying step that gives an impact to the concrete surface facing one end of the sheath tube; Propagation waveform receiving step for detecting vibration generated in the sheath tube by the impact as a propagation waveform provided on the concrete surface opposite to the other end of the sheath tube, and calculating the zero crossing time based on the propagation waveform Zero cross time calculating step, zero cross frequency calculating step for calculating zero cross frequency based on the calculated zero cross time, and zero cross frequency normalized value calculating step for calculating the zero cross frequency normalized value by normalizing the calculated zero cross frequency And the above-mentioned graph based on the calculated zero cross frequency normalized value. Characterized in that it comprises a determination step of determining the degree of filling.

  According to the present invention, it is possible to accurately inspect the degree of filling of the grout in the sheath tube without holding concrete, and the number of processes such as lifting and repair after lifting is reduced. It is greatly reduced and measurement efficiency is improved. In addition, it is possible to prevent intrusion of rainwater and the like due to repairs after the suspension.

  Furthermore, the inspection can be performed without being affected by the length, material, and steel wire / rod of the PC steel material.

  In addition, the determination of unfilled can be performed by simply observing the received waveform or by automatic determination, suppressing the occurrence of variation by the measurer, and making the measurement more efficient with the measuring jig. .

  FIG. 1 is a schematic diagram illustrating a sheath tube grout filling degree inspection apparatus 1 according to an embodiment of the present invention, FIG. 2 is a schematic view illustrating a striking jig 10 of the filling degree inspection apparatus 1, and FIG. FIG. 4 is a graph showing an example of inspection data for grout filling in the filling degree inspection apparatus 1, FIG. 5 is a graph showing an example of inspection data for unfilled grout, and FIG. 6 is a degree of filling. FIG. 7 is an explanatory view showing a state of propagation of impact according to the present invention. In addition, D in FIG. 7 has shown typically the elastic wave which generate | occur | produces by impact.

  The inspection object by the filling degree inspection device 1 is, for example, a sheath tube 90 provided inside a bridge of an expressway (concrete structure) 100. The sheath tube 90 is provided with, for example, a plurality of steel wires 91 therein, and is filled with a grout 92 so that the steel wires 91 are not corroded. In such a sheath tube 90, the unfilled grout 92 is discriminated. In some cases, a steel rod having a diameter larger than that of the above-described steel wire 91 may be used inside the sheath tube, but in the present embodiment, the description will be given in the case of a steel wire.

  As shown in FIG. 1, the in-sheath tube grout filling degree inspection device 1 includes an impact jig 10 bonded to the surface of concrete 101 at a position facing the center of the end of the sheath tube 90, and an impact jig 10. The impact applicator 20 provided so as to be able to apply an impact, the trigger waveform receiving sensor 30 provided in the vicinity of the striking jig 10, and the end of the sheath tube 90 where the striking jig 10 is installed A propagation waveform receiving sensor 40 provided on the surface of the concrete 101 facing the other end of the sheath tube 90, a trigger waveform receiving sensor 30 and a detector such as an oscilloscope connected to the propagation waveform receiving sensor 40 (for example, Discriminating means) 50.

  As shown in FIGS. 2 and 3, the impact jig 10 has a square impact metal plate 11 to which an impact is applied by an impact applicator 20 and an end that can support the impact metal plate 11 on the surface of the concrete 101. It has a support arm 12 provided at three locations, and a suction cup 13 provided at the tip of the support arm 12 and capable of being adsorbed to the concrete 101 surface. In addition, an adhesive medium 60 is provided between the concrete 101 surface and the striking jig 10 and has an adhesive property that allows the elastic wave to be efficiently incident on the engaged surface. Yes. One surface of the adhesive medium 60 is bonded or bonded to the concrete 101 surface, and the other surface is bonded to the impact metal plate 11 of the impact jig 10.

  Connected between the propagation waveform receiving sensor 40 and the detector 50 are a filter 70 for removing noise of the propagation waveform received by the propagation waveform receiving sensor 40 and an amplifier 80 for amplifying the propagation waveform. Yes. This improves the SN ratio.

  The detector 50 includes a first CH 51 that detects a trigger waveform and a second CH 52 that detects a propagation waveform, and can compare the trigger waveform and the propagation waveform. Further, the detector 50 performs processing as will be described later based on the detected waveform to determine filling / unfilling. The detector 50 is configured not only to display the discrimination result but also to display the result of processing the detected waveform as a graph so that the operator can determine the filling degree.

  In the sheath tube grout filling degree inspection apparatus 1 configured as described above, the filling degree inspection is performed based on the following principle. That is, by applying an impact to the impacting metal plate 11 of the impacting jig 10 with the impact applicator 20, the elastic wave generated by applying the impact propagates on the inner surface of the concrete 101 and reaches the steel wire 91 of the sheath tube 90. Propagated. At this time, the trigger waveform when the impact is applied is received by the trigger waveform receiving sensor 30, and the received trigger waveform is detected by the first CH 51 of the detector 50.

  The propagation waveform receiving sensor 40 receives the propagation waveform propagated through the steel wire 91, passes the received propagation waveform through the filter 70, removes noise, amplifies the propagation waveform by the amplifier 80, and detects the propagation waveform. 50 second CHs 52 are detected.

  When the grout 92 of the sheath tube 90 is filled, as shown in FIG. 4, the time To when the propagation waveform reaches can be measured. On the other hand, when the grout 92 of the sheath tube 90 is not filled, as shown in FIG. 5, the propagation waveform in the vicinity of the time To when the propagation waveform arrives shows a high frequency. That is, there is a clear difference in the propagation waveform between when the grout 92 is filled and when it is not filled. By analyzing this difference, it is determined whether the grout 92 is filled or not filled in the sheath tube 90. it can.

  Next, the method for inspecting the grout filling degree in the sheath tube will be described with reference to the flowchart of FIG. For convenience of explanation, graphs used as an example of grout filling / unfilling do not necessarily use the same data.

  The adhesive medium 60 is applied to the concrete 101 surface corresponding to the center of the end of the sheath tube 90 provided inside the bridge of the highway 100. Next, the hammering jig 10 is installed on the concrete 101 surface by the adhesive medium 60 applied to the concrete 101 surface and the suction cup 13 provided on the hammering jig 10. Further, the trigger waveform receiving sensor 30 is installed on the surface of the concrete 101 in the vicinity of the hitting jig 10 (first process P1).

  As shown in FIG. 1, the propagation waveform receiving sensor 40 is attached to the surface of the concrete 101 corresponding to the center of the sheath tube 90 end, which is the other end of the sheath tube 90 where the impact jig 10 is installed (No. 1). 2 process P2).

  An impact is applied to the impact metal plate 11 of the impact jig 10 by the impact applicator 20 (third process P3). For example, the impact applicator 20 may use a hammer manually. The impact applied to the striking jig 10 is incident on the concrete 101 through the adhesive medium 60. As shown in FIG. 7, the elastic wave D incident on the concrete 101 by applying an impact spreads radially and is transmitted to the sheath tube 90. Due to the elastic wave D, a new vibration wave, which will be described later, is generated inside the sheath tube 90 and propagated to the surface of the concrete 101 facing the impact application side, that is, to the propagation waveform receiving sensor 40.

  The elastic wave (propagation waveform) propagated through the steel wire 91 to the propagation waveform reception sensor 40 in the third step P3 is received by the propagation waveform reception sensor 40, and the propagation waveform is detected by the detector 50 through the filter 70 and the amplifier 80. Detect with 2CH52. Further, the trigger waveform receiving sensor 30 receives the trigger waveform at the time of applying the shock, and detects it with the first CH 51 of the detector 50 (fourth step P4).

  A zero crossing time Zn (n = 1, 2, 3,...) Of the detected propagation waveform is obtained (fifth step P5). FIG. 8 is a graph illustrating the zero crossing time. As shown in FIG. 8, the propagation waveform zero-crossing time Zn is a time at the position where the amplitude value of the propagation waveform is 0 while the amplitude of the propagation waveform shifts from minus to plus on the time axis. Yes, the time To when the propagation waveform arrives is defined as a zero crossing time Z0. The zero crossing time Zn that is closest to the time To when the propagation waveform has reached is defined as Z1, and the subsequent zero crossing times are defined as Z2, Z3, Z4,.

  FIG. 9 shows an example for explaining the zero-crossing time Zn. As shown in FIG. 9, nine zero-crossing times Zn were detected, and the time To when the propagation waveform arrived was set as Z0, and sequentially set as Z1, Z2, Z3,. The propagation waveform shown in FIG. 9 is a propagation waveform in which the grout 92 of the sheath tube 90 shown in FIG. 5 is not filled, and has a high frequency from the zero cross time Z1 to Z6 in the vicinity of the zero cross time Z0.

  Based on the zero cross time Zn calculated in the fifth step P5, the zero cross frequency fzn (n = 1, 2, 3,...) Is calculated (sixth step P6).

First, the zero cross period Tzn (n = 1, 2, 3,...)
Tzn = Zn-Z (n-1)
Ask from. The zero cross period Tzn indicates a difference between adjacent zero cross times.

Next, when the zero cross frequency fzn is obtained from the zero cross period Tzn,
fzn = 1 / Tzn
It becomes.

  FIG. 10 is a graph showing an example of the zero cross frequency fzn. Here, the zero cross frequency of the propagation waveform in which the grout 92 is unfilled is fazn (n = 1, 2, 3,...), And the zero cross frequency of the propagation waveform in which the grout 92 is filled is fbzn (n = 1, 2, 3,. …). In addition, the vertical axis of the graph of FIG. 10 indicates the zero cross frequency fzn with the maximum value normalized to 1, and the horizontal axis indicates the variable n of the zero cross time Zn.

  As shown in FIG. 10, when the variable n is between 1 and 7, the zero cross frequency fazn is about 9 to 10 times higher than the zero cross frequency fbzn. Thus, since the zero cross frequency fazn when the sheath tube 90 is not filled with the grout 92 is higher than the zero cross frequency fbzn with which the grout 92 is filled, the zero cross frequency fzn can be easily detected and analyzed. Whether the grout 92 of the sheath tube 90 is filled or not can be determined.

  The process up to the sixth step is a case where the test result is artificially determined by a measurer or the like. Hereinafter, a calculation method for calculating data necessary for automatically determining the test result by a personal computer or the like will be described. In the test results shown in the graph of FIG. 10, when the variable n shifts from 7 to 8, the zero cross frequency fzn changes greatly. By displaying the graph of FIG. 10 on the detector 50, the operator may determine whether the filling is performed or not.

  Furthermore, when analyzing automatically, normalization is performed for such a change, and whether the grout 92 is filled or not is determined.

The absolute value FFazn (n = 1, 2, 3,...) Of the difference between adjacent fazn (n = 1, 2), (n = 2, 3),... Of the zero cross frequency fazn shown in FIG.
FFazn = | faz (n) −faz (n−1) |
Similarly, the absolute value FFbzn (n = 1, 2, 3,...) Of the difference between fbzn (n = 1, 2), (n = 2, 3),... Adjacent to the zero cross frequency fbzn is calculated as follows.
FFbzn = | fbz (n) −fbz (n−1) |
And calculate.

  FIG. 11 is a graph showing normalized FFzn (n = 1, 2, 3,...). Here, FFzn is normalized with a maximum value of 1, the absolute value FFzn of the difference is shown on the vertical axis of the graph, and the variable n such as the zero cross time Zn is shown on the horizontal axis. The absolute value FFazn of the adjacent difference fazn of the zero-crossing frequency of the propagation waveform when the grout 92 is not filled, and the absolute value FFbzn of the adjacent difference fbzn of the zero-crossing frequency of the propagation waveform filled with the grout 92 are input to the graph. (7th process P7).

  In FIG. 11, a comparison is made between filled and unfilled. However, when the sheath tube 90 is actually inspected, the absolute value of the difference in the zero-crossing frequency fzn of the propagation waveform detected during the filling degree inspection of the inspection grout 92 is shown. FFzn is calculated and inspection information is input to the graph shown in FIG.

  In the example shown in FIG. 11, it can be determined that the value of FFazn (n = 7) when the variable n is 7 and the grout 92 is not filled is about 9 to 10 times larger than the other values. Further, it can be determined that the value of FFbzn when the grout 92 is filled is almost unchanged.

  In FIG. 11 graphed in the seventh step P7, the value FFo of the boundary between filled and unfilled is set by, for example, an experiment. When the value of FFzn calculated in the seventh step P7 exceeds the set value FFo, it is determined that the grout 92 in the measured sheath 90 is not filled. If the set value FFO is not exceeded, it is determined that the grout 92 in the measured sheath 90 is filled. (Eighth process P8) Thus, the determination can be easily performed by converting the coordinates from FIG. 10 to FIG.

  Instead of coordinate conversion, a method may be used in which areas of fazn and fbzn in FIG. 10 are obtained, and when the area is large, it is determined that the grout 92 is not filled.

  Next, the reason why the waveform received by the propagation receiving sensor 40 when the grout 92 provided in the sheath tube 90 is not filled becomes a waveform having a frequency higher than the frequency of the elastic wave generated by applying the impact will be described. . FIG. 12 is an explanatory diagram showing the propagation of elastic waves in the concrete 101 and the sheath tube 90 (when not filled) when an impact is applied. In FIG. 12, D is the elastic wave, K is the vibration of the steel wire 91 (steel wire vibration), S is the vibration of the sheath tube 90 (sheath tube vibration), T is the elastic wave propagating in the concrete 101, U Indicates an elastic wave generated by a phenomenon described later. In addition, the sheath tube 90 shown in FIG. 12 clearly shows the grout filled portion 94 and the grout unfilled portion 95 for convenience of explanation, and the number of the steel wires 91 may be different from the actual sheath tube 4. It was a book.

  As shown in FIG. 12, an impact is applied to the impact jig 10 by the impact applicator 20. This impact becomes elastic wave D and enters the concrete. The incident elastic wave D is divided into an elastic wave T propagating in the concrete 101 and an elastic wave that vibrates the sheath tube 90 from the concrete 101.

  Since the length of the sheath tube 90 is about 220 times as large as the diameter of the sheath tube 90 (for example, when the sheath tube 90 has a diameter φ = 45 mm and a length = 10 m), the sheath tube 90 is not like the sheath tube vibration S. By vibrating, air column resonance is generated inside the sheath tube 90. This air column resonance is generated in the unfilled portion 95 of the sheath tube 90 and vibrates the steel wire 91. In the steel wire 91, the steel wire vibration K sequentially occurs in each steel wire 91 like the resonance phenomenon of a tuning fork. At this time, since the steel wires 91 mutually amplify vibration, the vibration frequency becomes higher. The elastic wave U having the increased vibration frequency propagates through the steel wire 91, further propagates through the concrete 101, and is received by the propagation waveform receiving sensor 40.

  As described above, when the sheath tube 90 has the grout unfilled portion 95, a waveform having a frequency higher than the frequency of the elastic wave region generated by applying an impact is generated. After this high frequency elastic wave U is received by the propagation waveform receiving sensor 40, the elastic wave T propagated through the concrete 101 is received by the propagation waveform receiving sensor 40. For this reason, as shown in FIG. 5 and FIG. 9, when the grout 92 is unfilled (the sheath tube 90 has the grout unfilled portion 95), a high-frequency propagation waveform near the time To when the propagation waveform arrives. Is detected and the grout 92 is filled (the sheath tube 90 does not have the grout unfilled portion 95), a high-frequency propagation waveform is not observed.

  For convenience of explanation, the sheath tube 90 having the steel wire 91 has been described. However, since the same action occurs not only in the steel wire 91 but also in the steel rod, the grout filling degree inspection device 1 in the sheath tube according to the present invention is used. Thus, the sheath tube 90 having the steel rod or the steel wire 91 can be handled.

  As described above, according to the grout filling degree inspection apparatus 1 in the sheath pipe according to the present embodiment, it is not necessary to hang the concrete 101 and expose the PC steel material, so that the inspection cost can be greatly reduced and the inspection efficiency is also improved. To do. In addition, since no repair is required after hang-up, there is no need for repair costs, and there is no risk of rainwater or the like penetrating into the sheath tube due to aged deterioration of the repair site or a repair error. In addition, since it is an inspection method that is not affected by the dimensions and materials of PC steel, and is compatible with sheath pipes that have PC steel such as steel wires and steel rods, sheaths currently used for bridges, etc. Can be used for tubes. In addition, the determination of filling / unfilling at the time of inspection can be performed with high accuracy regardless of the ability of the measurer because the received propagation waveform can be visually checked or automatically determined by a personal computer, for example. is there.

  Further, since the filled / unfilled grout 92 can be identified from the detected waveform shape, an absolute evaluation is possible. This is not a relative evaluation in which, for example, 100 sheath tubes are inspected, and a sheath tube in which an abnormal test result is measured is determined to be unfilled. -Since it is absolute evaluation which can judge unfilling, by using the filling degree test | inspection apparatus 1, an inspection precision, a determination error, etc. can be reduced as much as possible. Furthermore, since various measuring jigs have been developed, it is possible to improve the efficiency of measurement.

  FIG. 13 is a front view showing a hitting metal plate 14 according to a first modification of the filling degree inspection apparatus 1. In FIG. 13, the same functional parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The hitting metal plate 14 has roundness 14 a at the corner of the surface in contact with the adhesive medium 60. By using such a hitting metal plate 14, even when an impact is applied by the impact applicator 20, it is possible to suppress the generation of noise due to the corners.

  FIG. 14 is a front view showing an impact metal plate 15 according to a second modification of the filling degree inspection apparatus 1. In FIG. 14, the same functional parts as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The hitting metal plate 15 includes, for example, oblique through holes 15a and through holes 15b on the diagonal lines and side surfaces of the hitting metal plate 15. Thus, by providing the through hole 15a and the through hole 15b, it is possible to suppress the occurrence of standing waves that cause noise generated on the four sides and the diagonal of the square when an impact is applied.

  FIG. 15 is a front view showing an impact metal plate 16 according to a third modification of the filling degree inspection apparatus 1. In FIG. 15, the same functional parts as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The hitting metal plate 16 is formed in a rectangular shape. By forming the hitting metal plate 16 in this way, the hitting metal plate 16 can suppress a standing wave having four long sides as a half-long wave compared to the square hitting metal plate 15. It becomes.

  FIG. 16 is a front view showing an impact metal plate 17 according to a fourth modification of the filling degree inspection apparatus 1. In FIG. 16, the same functional parts as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The hitting metal plate 17 is formed in a circular shape. By forming the hitting metal plate 17 in this manner, it is possible to suppress the occurrence of standing waves because there are no square four sides and diagonal lines.

  FIG. 17 is a front view showing a hitting metal plate 18 according to a fifth modification of the filling degree inspection apparatus 1. In FIG. 17, the same functional parts as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The hitting metal plate 18 is formed in an elliptical shape. By forming the hitting metal plate 18 in this way, there are no four sides and diagonal lines of the square, and it is less likely to generate a standing wave than a circle, thereby suppressing the generation of a standing wave. Is possible.

  The present invention is not limited to the above embodiment. For example, although the support arm 12 described above has been described as being provided at the three positions of the end portion of the metal plate 11 for impact, the support arm 12 can be applied even when the number is not three. The striking jig 10 and the impact applicator 20 have been described separately. However, the striking jig and the impact applicator may be formed integrally. In addition, various modifications can be made without departing from the scope of the present invention.

The schematic diagram which shows the filling degree test | inspection apparatus of the grout in a sheath pipe | tube which concerns on one embodiment of this invention. The schematic diagram which shows the jig | tool for striking of the same filling degree inspection apparatus. The front view of the jig | tool for impact. The graph which shows an example of inspection data of grout filling in this filling degree inspection device. The graph which shows an example of the inspection data of the grout unfilling in this filling degree inspection apparatus. The flowchart which shows the inspection process of a filling degree inspection apparatus. Explanatory drawing which shows the propagation state of the impact of this invention. The graph which shows description of zero crossing time. The graph which shows description of zero crossing time Zn. The graph which shows an example of zero cross frequency fzn. The graph which shows normalized FFzn. Explanatory drawing which shows propagation of the elastic wave of concrete and a sheath pipe | tube (at the time of unfilling) when an impact is applied to the same invention. The front view which shows the metal plate for striking which concerns on the 1st modification of this invention. The front view which shows the metal plate for striking which concerns on the 2nd modification of the same invention. The front view which shows the metal plate for striking which concerns on the 3rd modification of the same invention. The front view which shows the metal plate for striking which concerns on the 4th modification of the same invention. The front view which shows the metal plate for striking which concerns on the 5th modification of the same invention. Explanatory drawing which shows the principle of the conventional grout filling degree inspection apparatus in a sheath pipe | tube. The graph which shows an example of the result detected with the same filling degree inspection apparatus. Explanatory drawing which shows an example of a bridge inspection with the same filling degree inspection apparatus. Explanatory drawing which shows an example of a bridge inspection with the same filling degree inspection apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Filling degree inspection apparatus, 10 ... Impact jig | tool, 20 ... Impact applicator, 30 ... Trigger waveform receiving sensor, 40 ... Propagation waveform receiving sensor, 50 ... Detector, 51 ... Channel 1 (1st CH), 52 ... Channel 2 (second CH), 70 ... Filter, 80 ... Amplifier, 90 ... Sheath tube, 91 ... Steel wire, 92 ... Grout, 100 ... Highway, 101 ... Concrete.

Claims (9)

In the filling degree inspection device that is installed inside the concrete structure and inspects the filling degree of the grout of the sheath tube having a steel material,
An impact applying means for impacting the concrete surface facing one end of the sheath tube;
A propagation waveform receiving sensor that is provided on the concrete surface facing the other end of the sheath tube and detects vibration generated in the sheath tube by the impact as a propagation waveform;
Zero-cross time calculating means for calculating the zero-cross time based on the propagation waveform;
Zero-cross frequency calculating means for calculating a zero-cross frequency based on the calculated zero-cross time;
A zero-cross frequency normalized value calculating means for normalizing the calculated zero-cross frequency and calculating a zero-cross frequency normalized value;
A filling degree inspection apparatus comprising: a determining unit that determines the filling degree of the grout based on the calculated zero cross frequency normalized value.   The filling degree inspection apparatus according to claim 1, wherein the determination unit is a display device that displays the zero-cross frequency normalized value.   The said discrimination | determination means is provided with the comparison means which compares the absolute value of the difference of the said zero cross frequency normalized value which adjoins each other, and the threshold value which distinguishes normality / abnormality. Filling degree inspection device. The impact applying means includes an adhesive medium provided on the concrete surface,
An impact jig provided on the adhesive medium;
The filling degree inspection apparatus according to claim 1, further comprising an impact applicator provided to the impact jig so as to be able to apply an impact. The striking jig is a striking metal plate to which an impact is applied,
A support arm provided on the metal plate for striking and supporting the metal plate for striking on the concrete;
The filling degree inspection apparatus according to claim 4, further comprising a suction cup provided at a portion of the support arm in contact with the concrete.   6. The filling degree inspection device according to claim 5, wherein the hitting metal plate is formed with suppression means for suppressing the occurrence of standing waves. In the filling degree inspection method for inspecting the filling degree of the grout of the sheath tube having a steel material installed inside the concrete structure,
An impact applying step for impacting the concrete surface facing one end of the sheath tube;
A propagation waveform receiving step that is provided on the concrete surface opposite to the other end of the sheath tube and detects vibration generated in the sheath tube by the impact as a propagation waveform;
A zero cross time calculating step for calculating a zero cross time based on the propagation waveform;
A zero cross frequency calculating step of calculating a zero cross frequency based on the calculated zero cross time;
A zero cross frequency normalized value calculating step of normalizing the calculated zero cross frequency to calculate a zero cross frequency normalized value;
And a determination step of determining the degree of filling of the grout based on the calculated zero cross frequency normalized value.   The filling degree inspection method according to claim 7, wherein the discrimination step displays the zero cross frequency normalized value. The discrimination step includes the absolute value of the difference between the zero cross frequency normalized values adjacent to each other,
The filling degree inspection method according to claim 7 , further comprising a comparison unit that compares a threshold value for distinguishing from an abnormality.

Images